As well known to those skilled in the art, in an air conditioning system provided in a building for air conditioning of rooms, a diffuser is installed in the ceiling of the room, so that cold air is supplied into a room therethrough in the summer and hot air is supplied into the room therethrough in the winter.
In the room, convection currents, in which hot air rises while cold air sinks, always arise. Therefore, it is preferable that the diffuser be set such that cold air is supplied from the diffuser towards the ceiling and hot air is vertically supplied from the diffuser towards the bottom of the room.
In other words, when cold air is supplied towards the ceiling, the cold air can be dispersed from the ceiling towards the bottom of the room by convection. Thus, air-cooling is efficiently executed. As well, because the cold air is not directly blown towards people in front of the diffuser, the people are prevented from becoming excessively chilled.
Meanwhile, when hot air is supplied towards the bottom of the room, the hot air can be dispersed from the bottom towards the ceiling by convection, thus promoting efficient and rapid air-heating.
For ease of description, the supply of air from the diffuser towards the ceiling is described as the horizontal air supply, and the supply of air from the diffuser towards the bottom is described as the vertical air supply.
Although diffusers, which supply cold or hot air in a horizontal or vertical direction, have been proposed, most of the conventional diffusers are manually manipulated. Therefore, each season the conventional arts require users to change air supply direction of all diffusers, which are installed in many rooms of the building, thus inconveniencing the users.
To solve the above-mentioned problems, recently, diffusers that change an air supply direction using a temperature sensing cylinder having therein a wax that is expanded or contracted depending on the temperature of supply air, have been developed. However, because these diffusers have complex structures, there are problems in that the incidence of malfunction is increased and an air supply direction may be incorrectly changed.